Formant transitions provide context-dependent acoustic cues that can be
interpreted in terms of the articulatory kinematics involved in moving from a
consonant to a vowel. Formant frequencies were measured at identified acoustic
landmarks for eight English fricatives preceding front, back, and back-rounded
vowels. Formant onset times designated the point when the energy increased most
rapidly and evidence of the first formant was first observed. Comparing the
two-dimensional representation of F2xF3 onset frequencies along the voicing
dimension showed the voiceless fricatives to be more dependent on vowel
context. The onset frequencies for voiced fricatives reflect a more extreme
supraglottal posture, while the voiceless fricative measures can be considered
to be at a point closer to the vowel because voicing begins at a later time
relative to the oral release gesture. Formant structure in the noise before the
release, to the extent that it is visible in the consonantal interval prior to
voicing onset, can provide additional place information for voiceless
fricatives. Formant onset data are compared with measurements reported from
investigations of place categorization of stop consonants. [Work supported by
NIH.]